Exhaust System Guidelines-Towsport - Mercury MerCruiser Service Manual

IMPORTANT: The large diameter of the mount trunnion must not extend over 45 mm (1‑3/4 in.) from the mount brackets
on any of the mounts.
6. After the engine has been properly aligned, secure the engine mounts.
7. Tighten the bolts to the specified torque.
Description
Clamping bolts and nuts
8. Tighten the locknuts on all four mounts.
9. Bend one of the tabs on the tab washer down onto the flat of the adjusting nut.
IMPORTANT: All flange bolts must be SAE grade 8 (metric grade 10.9) or better, with a shoulder (grip length) sufficient to
pass through the mating face plane of the flanges.
10. Secure the flange coupling together with bolts, lockwashers, and nuts. Tighten the fasteners to the specified torque.
a
Description
Flange coupling bolts
a. If the propeller shaft flange has set screws, remove the set screws, and mark the dimple locations using a transfer
punch.
b. To drill dimples, remove the propeller shaft flange and drill shallow dimples at locations marked with a punch.
c. Install the propeller shaft flange and tighten the bolts to the specified torque. Install the set screws and tighten
securely. Safety wire the set screws to ensure that they do not loosen.
d
e
Exhaust System Guidelines—TowSport
IMPORTANT: If the provided system is not used with the engine, no warranty claims will be allowed for water ingestion issues.
These engines are equipped with a wet exhaust system in which exhaust is mixed with water in the exhaust elbows. This cools
the exhaust and allows the use of heat‑resistant rubber hose on the outlet side of the system. These specifications must be
observed by the OEM and muffler manufacturer when installing the exhaust system:
• Use heat resistant exhaust hose that complies with specifications SAE J2006 or UL 1129 (ABYC standard).
• Exhaust hoses should be no smaller than the minimum sizes. Use larger hoses on applications with long hose runs.
Model
All Models
90-8M0099748 eng DECEMBER 2015
b
b
a - Propeller shaft flange
b - Bolts
c
c - Set screws
d - Safety wire
e - Transmission output flange
a
7627
Minimum Exhaust Hose Size
a - Bolts
b - Transmission flange
7626
Dual Muffler outlet
88.9 mm to 102 mm (3.5 in.) to (4.0 in.)
© 2016 Mercury Marine
Installation
Nm lb‑in.
68 – 50.2
Nm lb‑in.
68 – 50.2
Page 2B-33
lb‑ft
lb‑ft